Protective packaging structures are often used when an article to be transported requires protection from physical shock, dust, dirt and other contaminants. For example, when shipping articles which may be relatively fragile, it is often desirable to package the article inside a box to protect the article from physical impacts to the box which may occur during loading, transit and unloading. In addition, when shipping sensitive electronic articles, such as computer components, it is often desirable to protect those components from dust and dirt. Aside from the shipping box itself, some additional structures are ordinarily needed to prevent the article from being damaged by uncontrolled movement within the box. Such additional structures have included paper or plastic dunnage, molded plastic foams, and foam-filled cushions, among others.
One useful form of packaging for especially fragile articles is referred to as suspension packaging, examples of which are disclosed in U.S. Pat. No. 4,852,743 to Louis H. Ridgeway and U.S. Pat. No. 5,388,701 to Devin C. Ridgeway. In suspension packaging, the article is suspended between two confronting sheets of plastic film. The sheets are usually attached to frames which are sized to fit securely within a selected size box. The fact that the article is not in contact with any substantially rigid surfaces protects it from physical shock. It is not necessary in all cases, however, for the article to be entirely suspended within the box, such as when packaging less fragile articles. In such cases, the extra space required for full suspension packaging becomes a less efficient use of such materials.
An alternative to suspension packaging is referred to as retention packaging, examples of which are disclosed in U.S. Pat. No. 5,678,695 to Devin C. Ridgeway et al. In retention packaging, an article is positioned between a sheet of flexible film and a rigid backing. The film is connected to folding side portions of the rigid backing such that the film is tightened against the article as the rigid side portions are folded away from the film. The folded structure fits within a selected box size which holds the article securely in place, but in contact on one side with a rigid surface. While retention packaging reduces the overall size of the packaging, placing the article between the flexible film and rigid backing is a cumbersome process and may increase the overall time needed to package each article. When packaging many thousands of articles, this incremental increase in time may have a substantial overall impact on shipping costs.
In a variant of the retention package described above, the package includes a rigid border extending around the entire periphery of a window opening, and side legs and end legs foldably connected to and supporting the border. A flexible film is connected to the underside of the border so that it extends across the window opening. An article to be packaged is placed on the film, and a series of four flaps connected to the four sides of the border are folded over the article to hold the article in place against the film. This packaging structure suffers from several drawbacks, including the need to hold the four flaps open in order to place the article on the film, the increased package size resulting from the requirement for a border extending around the entire periphery of the window opening, the need for a flap connected to each portion of the border to provide structural integrity to the border, and the need to increase the size of the window opening in order to accommodate articles which are thicker in cross-section.
There therefore exists a need for packaging structures which are easier and less time consuming to use than prior art packaging structures. Preferably, such structures will make efficient use of materials so as to be able to package articles in smaller containers than previously possible without sacrificing the strength of the packaging structure so as to risk damage to the articles packaged therein.